Hydrogenated resin esters and their production



Patented Nov. 16, 1937 HYDBOGENATED RESIN ESTERS AND THEIR PRODUCTIONIrvin W. Humphrey, Wilmington, Deb, assignor to Hercules Powder Company,Wilmington, 1 a corporation of Delaware No Drawing. Original applicationDecember 2, .1929, Serial No. 411,201. Renewed September 22, 1932.Patent No. 2,051,796, dated August 18, 1936. Divided and thisapplication October 3, 1932, Serial No. 636,015

28 Claims. (01. 260- 99.40)

invention relates to hydrogenated esters of unsaturated resin acids, forexample, of abietic acid, pimaric acid, the fossil resin acids, etc.,and more specifically relates to the hydrogenated polyhydric alcoholesters of these, acids and their production.

Hydrogenated polyhydric alcohol esters of unsaturated resin acids arefound to have substantial advantages in the commercial arts over thegenerally known ester gums. These hydrogenated esters, for example,offer the advantage that, on exposure, coatings containing them retaintheir flexibility and original color for a longer period thancorresponding .coatings containing the non-hydrogenatedpolyhydricalcohol esters and at the same time theypossess all of theadvantageous features of the known ester gums.

The hydrogenated polyhydric alcohol esters in accordance with thisinvention may be produced by esterifying a hydrogenated resin acid, asfor example, dihydro or 1 tetrahydro abietic or pimaric acid with apolyhydric alcohol, for example, propylene, ,or ethylene glycol,diethylene glycol, trimethylene glycol, erythritol, arabitol, xylitol,p'ent'aerythrite, mannitol, glycerol, etc. Alternatively a resin acid,as abietic acid, hydrogenated pimaric acid, etc), may be esterified witha polyhydrio alcohol. and the unsaturated ester subsequentlyhydrogenated, which is a preferable procedure.

As a further alternative, hydrogenation may be combined withesterification, as by heating the unsaturated resin acid with apolyhydric alcohol at atmospheric or higher pressure, depending upon theboiling-point of the alcohol, in the presence of a suitable catalyst, asplatinum, nickel, palladium, etc., while treating with hydrogen. 1

As an illustration of the preparation of a hydrogenated ester by.hydrogenating a polyhydric alcohol resin ester, about 2% of catalyticnickel is added to the glycerol ester of abietic acid, prepared byesterifying rosin, as such, or abietic acid with, for example, glycerol,and the ester heated to a temperature of about 250 C. under atmosphericpressure for about 15 hours while passing into the ester acurrent'oihydrogen. The time; required for-hydrogenation maybe shortened to abouttwo'hours by carrying out the treatment at an increased pressure; say200 pounds to the square inch. In this manner about of the double bondsmay be saturated with hydrogen. In effecting the hydrogenation, theester may, 01 course, be subjected to treatment in solution in analcohol, acetic acid, ethyl acetate, an ether or the like, underpressure" q I v A similar reaction may be carried outat room temperatureusing palladium as a catalyst. In

this .case'the glycerol ester is dissolved in a suitable solvent,for'example, ethyl acetate, rendered acid by the addition of a smallproportion of acid, as acetic acid. To five parts of glycerol ester ofrosin dissolved in ethyl acetate, one part of palladium may be added.The solution may then be shaken in an atmosphere of hydrogen, preferablyunder a pressure of, say, 40-60 pounds per square inch, at roomtemperature, or somewhat higher, until sufficient hydrogen'is absorbed.Upon filtering off the catalyst and evaporating the solvent a'hydrogenated glycerol ester results, about hydrogenated. r

In carrying out the hydrogenation of the polyhydric alcohol esterspressures may be used from atmospheric pressure up to around 2,000poundsper square inch. Other catalysts may also be used, among which maybementioned platinum, cobalt, nickel-copper, etc. The temperatures mayvary depending upon the properties of the substances involved and theproducts formed, as well as the activity'of the catalyst.

Instead of preparing a glycerol ester and then hydrogenating,the resinacid may be first hydrogenated and then esterified with the polyhydricalcohol. As-an illustration of this process, either the hydrogenatedrosin or resin acid, as dihydroor tetrahydro abietic acid is heated, ifdesired, under pressure in an autoclave, with a polyhydric alcohol, forexample,-glycerol or glycol either with or without an esterificationcatalyst such as boric anhydride. Alternatively an alkali salt or thehydrogenated acid may be treated with a halogen' derivative of 'thealcohol, for example, a chlorohydrin such as glycolchlorhydrin orglycerol dichlorhydrin, etc.

It is alsopossib'le to effect the hydrogenation and .esteriflcationsimultaneously, for example, by treating'the polyhydric alcohol, theunsaturated resin acid, and a catalyst, such as nickel, palladium, orplatinum, with hydrogen under pressure and at elevated temperatures. eThe various alternative hydrogenation cata lysts have already beenreferred to." The other conditions of. the reaction depend upon theproduct desired, the reagents, etc. and may vary considerably. Whilespecific examples involving glycerol, glycol, or their derivatives havebeen referred to above, it will be understood that strictly similarreactions occur using other less common polyhydric alcohols of the typenoted above.

The hydrogenated polyhydric alcohol esters in accordance with thisinvention are admirably adapted as ingredients for coating compositions,as varnishes, lacquers and the'like. in' substitution for unsaturatedresin esters and fossil resins, and in some cases are found valuable asplasticizers.

Comparative tests show that films containing hy- I drogenated polyhydricesters of the resin acids do not become yellow or crack with aging asreadily as do films containing non-hydrogenated esters. Hydrogenation ofthe glycerolv ester, for example, is an improvement even if only 50% orthe double bonds are saturated with hydrogen, but it is preferabletocarry the hydrogenation as near to completion as practical, preferablyat least to 75% saturation.

polyhydric alcohol.

8. The method oiv preparing a hydrogenated rosin acid'ester of glycerol,which includes esterl fying a hydrogenated rosin with glycerol. 9. Themethod of preparing .a hydrogenated rosin acid ester ofa glycol, whichincludes asterifying a hydrogenated rosin with a glycol.

It willbe understood that the esters in accordance withthe invention maybe produced from unsaturated resinacids, as contained in resins, asrosin, fossilresins, etc... or from the resin acids as such, as abieticacid, pimaric acid, etc.

This application constitutes" a division of the application for UnitedStates Letters Patent heretofore filed by me,.Seri al No. 411,201, fliedDecember2, 1929,1'or Hydrogenated resin esters and their production,renewed Sept. 22, 1932, and has matured into Patent No. 2,05l,796, datedAugust 18,1936. I

What I claim' and desire to protect by Letters Patent is:

1. The method of preparing a hydrogenated resin acid ester of avpolyhydric alcohol, which includes esterifying a hydrogenated resin acidwith a polyhydricalcohol. I

2. The method of preparing a hydrogenated resin acid ester of glycerol,which includes esterifying a hydrogenated resin acid with glycerol.

3. The ,method of preparing a hydrogenated resin acid ester of a glycol,which includes esterifying a hydrogenated resin acid with a glycol.

-4. The method of preparing a hydrogenated abietic-acid ester ofapolyhydricalcohol, which includes vesterifying hydrogenated v abieticacid with apolyhydric alcohol.

5. The method of, preparing a hydrogenated I abietic acid ester ofglycerol, which includes esterifying; hydrogenated abietic acid withglycerol.

6. The method of preparing a hydrogenated abietic acid ester of aglycol, which includes esterifying-hydrogenated abietic acid with aglycol.

7. The method ofpreparingia hydrogenated rosin acid esteriof apolyhydric alcohol, which includes esterifying a hydrogenated rosin with9.

10. The method of preparing a hydrogenated rosin acid ester of apolyhydric aliphatic alcohol, which includes esterifying a hydrogenatedrosin with a polyhydric aliphatic alcohol.

' 11. The method of preparing a hydrogenated abietic acid ester of aglycol, which includes esterifying hydrogenated abietic acid withethylene glycol.

12. The method of preparing a hydrogenated rosin acid ester of a glycol,which includes esterifying a hydrogenated rosin with ethylene glycol.

13. The method of preparing a hydrogenated rosin acid ester of apolyhydric alcohol, which includes esterlfying a hydrogenated rosin witha polyhydric alcohol byheating under pressure.

14 The method of preparing a hydrogenated rosin acid ester of glycerol,which includes eaterifying a hydrogenated rosin with glycerol by heatingunder pressure.

15. The method of preparing ahydrogenated rosin acid esteroi' a glycol,which includes esterifying a hydrogenatedrosinwith a glycol by heatingunder pressure.

16. The method or preparing a hydrogenated rosin acid ester of apolyhydric alcohol, which includes esterifying a hydrogenated rosin witha polyhydric alcohol by heating under pressure in' the presence of anesterification catalyst.

1'7. The-methodof preparing a hydrogenated rosin acid ester of glycerol,which includes esterifying a hydrogenated resin with glycerol by heatingunder pressure in the presence oi an esteriflcation catalyst.

18. The method of preparing a hydrogenated rosin acid ester of a glycol,which includes esterifying a hydrogenated rosin with'a glycol by heatingunder pressure in the presence'oi an esteriflcation catalyst.

19. The method of preparing a hydrogenated rosin acid ester of apolyhydric alcohol, which includes esterii'ying a hydrogenated rosinwith a polyhydric alcohol by heating in the presence of anesteriiication catalyst. g

20. The method of preparing a hydrogenated resin acid ester of apolyhydric alcohol, which includes simultaneously hydrogenating a rosinacid and esterifying with a polyhydric alcohol.

v 21. The method-of preparing a hydrogenated pimaric-acid ester of apolyhydric alcohol, which includes esterifying hydrogenated pimaric acidwith a polyhydric alcohol.

22. The method of preparing a hydrogenated pimaric acid ester ofglycerol, which includes esteritying hydrogenated pimaric acid withglycerol. F

23. The method of preparing a hydrogenated pimaric acid esterof aglycol, which includes esterifying hydrogenated pimaric acid withethylene glycol. V

24. As a new product a polyhydric alcohol ester of a tetrahydro rosinacid.

25; As a new product a polyhydric alcohol ester oi a hydrogenatedpimaric acid.

26. As a new product a polyhydric alcohol ester of. a rosin'acid havinga hydrogen saturation of aboutv 50 percent to about 75 percent.

27. As a new product a polyhydric alcohol 7 ester of. a tetrahydroresiniacid.

28 As a new product a polyhydric alcohol ester of, abietic acid having ahydrogen saturation' about 50 percent to aboutlfi percent.

IRVIN W. HUMPHREY.

